Quick and Easy-to-Install Replacement Pads Keep spares at the ready just in case! Be prepared for a leak before it starts, but in the event your leak prevention valve has been triggered, our replacement pads will get you up and running again in seconds. It is never good to run your system without an expansion pad as costly water damage could occur. Keep a few of these on hand just in case. Fits Most Systems Our compressed expandable pads with wider design are designed to fit snugly inside the activation chamber of 17mm-19mm models to ensure they expand vertically effectively triggering the shut off valve. Other pads that fit loosely may not expand correctly, extending the time water is leaking before the device is triggered. Specifications Height 3/8″ (12mm) Diameter 3/4″ (20mm) Snug Fit Design Activation pads should fit tightly inside the trigger chamber to ensure a positive, vertical expansion. AROUND THE CLOCK PROTECTION: When water makes contact with the pad, our compact, dense sponge with a wide base allows for full vertical expansion utilizing the full pad tray ROBUST THICK PAD: Our pads are designed to fit snug in each device. Smaller tablets may expand slightly off-center and potentially not trigger the device properly VERSATILE: 20mm wide fits perfectly with most 20mm-22mm pad leak detector/water stop valves NOT COMPATIBLE with AQUASURE, METPURE, ICON, ISPRING or EXPRESS WATER systems. Please use 18mm pads CONVENIENT recloseable storage containers keep pads sealed until needed VALUE PACK of TEN replacement pads ensure you always have spares handy